This study will evaluate the hypothesis that in HIV-infected women receiving oral ZDV for medical indications, HIVIG administered monthly beginning at 20-30 wks gestation in combination with intravenous ZDV intrapartum, together with a single newborn dose of HIVIG within 12 hrs of birth in combination with 6 wks of newborn oral ZDV, reduces vertical HIV transmission compared with IVIG administered identically as a control agent.